Method of observing liquid for impurities using a transparent container with contrasting colors

ABSTRACT

The invention relates to a substantially transparent container for liquids on one side of which are opaque light and opaque dark areas of color observable through the container for evaluating contained liquid for particulate impurities. The container is particularly useful for pharmaceutical liquids.

This is a division of application Ser. No. 07/729,967, filed Jul. 15,1991, now U.S. Pat. No. 5,261,546. Application Ser. No. 07/729,967 is acontinuation application of application Ser. No. 07/459,802 filed May 1,1990, now abandoned.

FIELD OF THE INVENTION

The invention relates to a container for liquids that are evaluated forparticulate impurities by visual or mechanical means.

BACKGROUND OF THE INVENTION

Many different liquids must be packaged and sealed under conditions thatprevent contamination of the liquid by undesired particles. The liquidsmay be destined for use as reagents in analytical or diagnostictechniques requiring ultra-high purity or for administration asdiagnostic or therapeutic pharmaceuticals. In preparing and packagingsuch liquids, extensive precautions are taken to prevent contaminationby undesired particles. After preparation, the liquid is dispensed tocontainers which are then sealed. It is during packaging thatcontamination by undesired particles may occur in spite of precautions.These particles may render the liquid less valuable or inoperable fortheir intended purposes or may constitute a source of danger, inparticular in a pharmaceutical liquid for parenteral administration to apatient. In these cases, examination of each container, after sealing,is a compulsory requirement.

Various measures have been suggested to inspect liquids dispensed incontainers for the presence of undesired particles. A conventionalexamination method is a visual inspection which, although easy toperform and sufficiently reliable, is rather time-consuming. In such aninspection, the liquid is preferably illuminated with an artificiallight source, either directly or indirectly. The filled containers,after the liquid has been put in motion, usually are held successivelyagainst a black and a white background, so that light-colored anddark-colored particles, if any, in the liquid become visible. In such aninspection, it is desirable to keep the inspection time per container asshort as possible, without compromising the reliability of detection,merely for economic reasons. However, shortening of the time necessaryfor inspection is of prime importance when viewing or visuallyinspecting containers having a radioactive liquid for reasons of safety.Although the observer's eye is protected as well as possible duringviewing from radiation by, for example, positioning a transparent shieldof lead-glass between the observer and the container to be inspected, itcannot be entirely prevented. So the exposure time, i.e., the time inwhich the observer is exposed to radiation from the container, must beminimized.

In another usual method of inspecting liquids dispensed in containersfor the presence of undesired particles, suitable illuminating means anda detection apparatus are used. By illuminating the liquid in thecontainer in a special manner with the light of a carefully selectedlight source and then determining the intensity of the transmitted orscattered light by means of, for example, a photosensitive cell, acamera or a video camera with display screen, an impression can begained about the extent to which the liquid has been contaminated withparticles. Such an inspection device is disclosed in U.S. Pat. No.4,676,650.

These and similar devices are not only complex and hence sensitive todisturbances, and expensive as regards acquisition and maintenance, butthey are also not always satisfactory with regard to reliability anddetection sensitivity.

It is the object of the present invention to provide a more simple andreliable means of examining liquids for impurities which can be useduniversally, i.e., both for visual inspection and for use with detectionapparatus, and by which the examination can be facilitated so that theinspection time can be shortened as compared with the known visualinspection methods.

It is a further object to provide the means to more easily inspectliquids some time after packaging for changes such as sedimentation,crystalization, or gelling.

SUMMARY OF THE INVENTION

The present invention meets the above described objects by providingcontrasting dark and light colored backgrounds against which a liquid isobserved by applying to or incorporating in the container opaque areasof color. This is accomplished by adding the colored areas to a part ofa side of a substantially transparent container for the liquid. Theadvantage of this invention lies in that a single observation willdetect both light and dark particulate impurities and in that light beamdistortion through curved walls is avoided.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of a container according to the invention.

Reference numeral 1 in the drawing denotes a sealed vial which containsa liquid 2. The wall of the vial comprises a rectangular area which ispartly white 3 and black 4 and which has been provided in the glass wallby ceramic fusion printing. For inspection of the liquid the vial isilluminated with the light of a light source 5 through the flat bottom,the light source being positioned beneath the vial. The place of theobserver's eye 6 is also shown in the drawing.

DETAILED DESCRIPTION OF THE INVENTION

The invention is a container which provides the means of observingcontained liquid for particulate impurities. The container is composedof substantially transparent material for its side wall or walls. It mayalso have a transparent bottom. Opaque, contrasting areas of color areprovided on a part of a side wall. Preferably one white area and oneblack area are provided. They are preferably rectangular in shape andimmediately adjacent to one another.

The areas of color may cover a varying portion of the side area of thecontainer. There must be a portion left transparent for the observationto be made, but the minimum and maximum limits and the preferred totalarea of color may vary for different forms and sizes of containers. Themeans of observation to be used will also be determinative. For acylindrical container a preferred configuration is to cover one half ofthe side wall with color, half of the area being a light rectangle andhalf being a dark rectangle, more preferably being white and black,respectively.

The areas of color may be provided in a number of ways. For example, alabel may be placed on the outside of the container which has the colorareas printed on the reverse side, thereby visible through thecontainer. Permanent application to the container may be made by fusingthe color to the side wall, preferably to the exterior of the container.The colored areas are then not liable to be removed, damaged or becomedirty during handling and filling. This fusing may be accomplished byetching or ceramic fusion printing, for example.

Labelling over the colored areas may then be made either before or afterinspection. Problems with identification of the contents of thecontainer are prevented by an early labelling. By providing the labelover the contrasting color areas, the field of sight during theinspection is not limited, nor does the necessity exist of inspectingthe contents of the container at a given angle with the possibility ofannoying reflections at the glass.

The container must be substantialy transparent through the remainder ofthe side wall or walls, and preferably through the bottom. It may becomposed of a variety of materials, chosen for compatibility with thecontained liquid and other reasons such as cost. Glass a preferredcontainer composition for pharmaceutical liquids.

The shape of the container is chosen according to the function andproperties of the liquid. Examples of suitable container shapes arevials, ampules, bottles, and test tubes. However, the conformation ofthe container is not limited by the present invention, only by thecharacteristics and use of the contained liquid.

The advantages of the container having contrasting color areas accordingto the invention become most prominent during use, that is, when thecontainer has been filled with a liquid and closed or sealed. Forinspecting the contents for the presence of undesired particles, theliquid is put in motion and the container, with the colored area to therear, is placed at eye level of the observer or at the level of thedetection apparatus used, while the liquid is illuminated, preferablythrough the bottom of the container, that is, perpendicular to thedirection of observation. Such an illumination through a preferably flatbottom leads to sharper light beams and clearer scattering by theparticles, while annoying reflections in the case of light through thecurved wall are avoided. As a result of this the quality of theevaluation, both after visual and after instrumental observation, isimproved. The contrasting dark and light colored areas serve as abackground for the liquid to be inspected. As the background is presentnearer to the liquid, the contrast between the dark and the lightbackground is sharper. This improves the quality of the observation ascompared with the known method in which the container is heldsuccessively against a black background and a white background. Inaddition, when using a container according to the invention,displacement or rotation of the container during the inspection toenable inspection of the contents thereof against a varying backgroundmay no longer be necessary. As a result of this, fewer operations arerequired so that the inspection time is reduced. In visual observation,the eye gets tired less rapidly, while in instrumental observation thedetection apparatus need not be refocused again and again.

It will be obvious from the above that, compared with known containersnot providing contrasting dark and light colored areas, the containeraccording to the invention provides for a simple and reliable inspectionthat is facilitated so that the time required can be reduced. Inaddition to visual inspection, the container according to the inventionis also suited, as indicated hereinbefore, for instrumental observation,in which photoelectric, photographic or video techniques may be used.The results thus detected can, of course, be processed by means ofmodern techniques, for example, by means of a computer.

I claim:
 1. A method of examining a pharmaceutical liquid in atransparent container having areas of contrasting colors for detectingmulticolored impurities consisting of: positioning said transparentcontainer to align said areas of contrasting colors opposite a means ofhuman visual detection, putting said liquid within said container intomotion and illuminating said container by an illuminating meanssubstantially perpendicular to said means of human visual detection tocreate scattering of light beams by said impurities while avoidingreflections of said light beams.